public class Solution {
    public int maxProfit(int[] prices) {
        int len = prices.length;

        int[][] dp = new int[len][3];

        //初始化
        dp[0][0] -= prices[0];

        for (int i = 1; i < len; i++) {
            dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] - prices[i]);//买入
            dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][2]);//可交易
            dp[i][2] = dp[i - 1][0] + prices[i];//冷冻期
        }

        int ret = 0;

        for (int num : dp[len - 1]) {
            ret = ret >= num ? ret : num;
        }
        return ret;
    }
}
